1. Field of the Invention
The present invention generally relates to a device for mounting conduit. More specifically, this invention relates to a conduit mounting device used for connecting conduit of an air-conditioning system to a port associated with another component such as a compressor or another mounting device.
2. Description of the Prior Art
Prior to the present invention, many types of conduit mounting devices were developed for connecting a conduit to another component. For example, it is well known in the art to connect air-conditioning (a/c) tubes to an inlet or discharge port of an a/c component. Such mountings are typically made by means of a male-female coaxially threaded tube coupling or may be fixed within a block by a brazing process. Male-female coaxially threaded tube couplings are impractical for high volume manufacturing since they typically require manual assembly with multiple wrenches. Also, brazing processes typically involve expensive braze material, high temperature conditions, and undesirable fumes. Therefore several alternative approaches have been developed, including entrapping a tube within a block using formed tube features or entrapping a tube within a block using a retainer insert. However, the following approaches have many structural problems.
For example, U.S. Pat. No. 2,534,690 to Young, Jr., et al. discloses a tube longitudinally received into a U-shaped recess of a housing where a retainer clip is then inserted transversely into the same U-shaped recess to sandwich the tube therein. The retainer clip has bent tangs that engage longitudinally machined grooves in the U-shaped recess to lock the retainer clip transversely in place. The retainer clip further has bent flanges that straddle the longitudinal sides of the housing to lock the retainer clip longitudinally in place. Unfortunately, the longitudinally machined grooves in the housing require an expensive machining step, and further the retainer clip is a relatively convoluted and detailed stamping that is prone to tangling with other retainer clips during handling.
Another approach, U.S. Pat. No. 3,929,356 to DeVincent et al. teaches that an upset bead on the end of a tube is received into a stepped bore opening of a connecting block and then a spring retainer clip is removably inserted in a transverse slot from a position out of interference engagement with the annular bead on the tube to a position in which it engages the opposite side of the bead. The spring retainer clip is again a convoluted stamping with bent fingers, buttons, and seats that must fit into an expensive machined groove in the connecting block.
Similarly, U.S. Pat. No. 3,869,153 to DeVincent et al. proposes a tube mounting assembly in which an end of a tube having an upset bead is sandwiched between a mounting plate and a centrally apertured yoke on the tube that encircles the end thereof. The mounting plate is slotted to receive the tube and the yoke has spaced apart legs clamped around the side edges of the mounting plate to secure the tube. The '153 reference further discloses that each yoke is welded or brazed to the upset bead of the tube with which it is associated in order to effect a fluid-tight seal between the elements and to prevent axial or rotative movement of the yoke relative to the tube. Thus, the '153 reference requires the welding of parts and adds significantly more weight.
Finally, U.S. Pat. No. 5,860,681 to Slais teaches a tube received into a U-shaped recess of a block where a retainer insert is then inserted longitudinally into the same U-shaped recess to sandwich the tube therein. The retainer insert has straight tabs that engage longitudinally machined grooves in the U-shaped recess to lock the retainer insert transversely in place and thereby lock the tube in place. Further, the insert has a projection that engages a depression in the tube to prevent rotational movement. Although the retainer insert is a relatively simple molded part, the block includes expensive machined grooves and is relatively thick and heavy in order to accommodate the relatively long groove length needed for sufficient engagement. Furthermore, assembly of the retainer insert can be extremely difficult to perform by hand. The retainer insert must be assembled colinearly over the tube in an extremely tight fit therewith. Thus, the insert tends to bind with the tube during assembly.
All of the above references involve serious manufacturing drawbacks. Machining grooves in a solid block of metal is a relatively slow process that involves expensive cutting machines and tools and waste of material in machining chips. Further, most of the above references involve a convoluted metal stamping to retain the conduit to the block or housing. Such metal stampings are typically prone to tangling in material handling steps and also involve expensive die stamping processes. Although a metal stamped insert is not required in Slais, the insert nonetheless can be very difficult to assemble. Also, the Young, Jr. et al. reference and DeVincent et al. '356 reference involve means for retaining the tube that are not only complicated but also do not allow for preventing rotational movement of the tube within the mounting.
From the above it is clear that there is a need to provide a conduit mounting device that involves less complicated manufacturing processes, provides means for rotatably locking the conduit within the mounting assembly, and is easier to assemble than mountings of the prior art.